What’s certain is that millions of children in the United States are heading to school after the summer. Many are there for the first time, while others are in the final year of their formal education.

There will be tears, from some prekindergarten and kindergarten youngsters starting school, and from parents as they leave their new college students at the dorm.

Statistics make clear that those with college degrees generally will do better than their peers who do not graduate and that those who drop out from high school face an even more dismal future.

As the school year begins, some facts and figures about education in America:

HOW MANY STUDENTS ARE THERE?

The National Center for Education Statistics estimated that in 2013, 50.1 million children will be enrolled in U.S. public schools and 5.2 million will be in private school. That doesn’t include students who are home-schooled. The Education Department’s statistics arm also estimated there were 1.5 million U.S. students home-schooled in 2007; advocates of home schooling advocates put the number higher.

Enrollment in colleges and universities was estimated to reach a record 21.8 million this fall, according to NCES, the Education Department’s statistics arm.

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WHO’S TEACHING THEM?

There are about 3.3 million elementary and secondary public teachers in 2013, leading to a student teacher ratio of 15-to-1, NCES said.

The average teacher in a public school earned about $56,000 for the school year that ended in 2011, according to the agency. When adjusted for inflation, that salary is only 3 percent higher than it was for the year that ended in the spring of 1991.

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WHAT ABOUT SPENDING ON KIDS?

Teacher salaries are just part of the total spent on educating children. All told, NCES says $591 billion will be spent during the new school year. That breaks down to an average $11,810 for each student.

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WHAT ARE STUDENTS BEING TAUGHT?

The buzz word these days is Common Core. The Common Core State Standards establish benchmarks for student learning in math and reading. Forty-five states and the District of Columbia have adopted the standards, which critics decry as tantamount to a national curriculum. Supporters counter that the standards are necessary to ensure that high school graduates are ready for college or career.

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DRESSED AND EQUIPPED FOR SUCCESS

In some households, it is a tradition that children get a new outfit for that first day of school. But the cost is just a fraction of what parents pay to get their children ready for school. The National Retail Federation estimated that a family’s back-to-school spending for elementary and secondary school in 2013 would average about $634.78. In addition to clothing, supplies and electronics add to the total. That’s down more than $50 from the previous year.

For college students, there’s a higher cost. The federation said back-to-school spending for a college student would average $836.83 this year, also down from 2012.

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HOW SAFE IS MY STUDENT?

Last December’s shootings at Sandy Hook Elementary School in Newtown, Conn., brought questions about school security to the forefront.

More than 1.2 million students between ages 12 and 18 were victims of crimes at school in 2011, according to NCES and the Bureau of Justice Statistics. Of those, nearly half were violent crimes and 648,600 involved thefts, the agencies said.

Among students ages 5 to 18, there were 11 homicides and three suicides at school from July 1, 2010, to June 30, 2011.

The toll at Sandy Hook Elementary School was nearly double that number: 20 students were killed, along with six adults.

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JUMP START ON COLLEGE

More than 2 million students took 3.7 million Advanced Placement exams in 2012 in an attempt to earn college credit while still in high school, according the College Board, which administers the test.

The numbers have increased steadily since the 1955-56 school year, when 1,229 students took 2,199 exams.

But the increase in participation doesn’t necessarily translate into an increase in college credit. In 1992, 65.5 percent tests scored at least a 3, usually the minimum grade to earn credit. That dropped to 59.2 in 2012.

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COLLEGE STICKER SHOCK

The tuition and room and board bills already have arrived, and in many cases the due dates have passed. So what does it cost to attend a college or university these days? It depends on the type of school you go to.

Two-year, public community colleges will cost in-state students and their parents back about $10,550 this academic year, while the price tag for attending a four-year public institution of higher education averages about $17,860, according to the College Board. Choose to cross state lines to attend a public university? The price tag is an average $30,911.

The cost of a private, four-year college or university — $39,518, the College Board said.

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THAT’S A LOT OF MONEY. WHERE CAN I GET HELP?

Most families don’t foot the entire tuition bill, at least right away. According to NCES, 79 percent of undergraduates received some form of financial aid for the 2011-12 school year. Of that total, 59 percent got grants and 42 percent took out loans. Other aid includes veterans’ benefits and federal PLUS loans for parents.

Aid on average totaled $10,000, NCES reported.

After months of wrangling, Congress averted a doubling of federal student loan rates this fall. Rates on federal student loans will now be tied to the financial markets. For those taking out the federal Stafford loans this year, the rate is 3.9 percent interest rate for both subsidized and unsubsidized undergraduate loans, 5.4 percent for loans taken by graduate students and 6.4 percent for loans taken by parents.

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THE FINALE

At graduation ceremonies across the country this academic year, colleges and universities will grant students 943,000 associate’s degrees, 1.8 million bachelor’s degrees, 778,000 master’s degrees and 177,000 doctoral degrees, NCES said.

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IS THE COST WORTH IT?

Consider the financial benefits of finishing college.

The Census Bureau reports that adults with bachelor’s degree or more earned an average $81,761 in 2011. Those with high school degrees or GEDs earned an average $40,634, while the average wages for workers who didn’t finish ninth grade was $26,545.